Arc-lamp.



GQM. LITTLE.

ARC LAMP.

APPLICATION FILED APR. 6. 1915.

Patented May 28,1918.

2 SHEETSSHEET INVENTOR Georqp M. L/ff/p.

III

7IIIIIIIIIII ATTORN EY G. M. LITTLE.

ARC LAMP.

APPLICATION men APR. s. 1915.

Patented May 28,1918.

2 SHEETS-SHEET 2- WITNESSES;

INVENTUR George M. Liff/e.

ATTORNEY UNITED STATES PATENT oEEIoE.

GEORGE M. LITTLE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ARC-LAMP.

Specification of Letters Patent.

Patented May 28, 1918.

Application filed April 6, 1915. Serial No. 19,455.

To all whom it may concern:

Be it known that I, GEORGE M. LITTLE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Are- Lamps, of which the following is a specification.

My invention relates to electric arc lamps, and it has particular reference to the regulating and feeding mechanisms of focusing type are lamps in which consumable electrodes are burned.

The present invention provides a control mechanism in which the fractional resistance is substantially minimized by the elemination of many slidingly engaged surfaces which, during service, usually deteriorate and thereby affect the operating reliability of the lamp.

In the usual flaming arc lamps,the lower and; upper electrodes are consumed in the arcat different rates. In a common type of arc lamp, burning electrodes of a certain composition, the upper electrode is consumed in the are twice as rapidly as the lower. As a result, the lower electrode of a focusing-type arc lamp is fed into the are less rapidly than the upper electrode in the instance cited above, the lower electrode being fed into the arc one-half as rapidly as the upper electrode. To accomplish such feeding operations, the regulating and feeding mechanisms heretofore employed in focusing-type arc lamps have been rather complicated structures comprising a large number of cooperatively engaged elements between which abnormally high frictional resistance develops after the lamps have been in service for a shorttime.

One object of my invention is to provide a simple regulating and feeding mechanism that comprises a relatively small numberof elements or members between which negligible frictional resistance only may develop when the lamp is subjected to service conditions for any length of time.

Another object of my invention is to provide a simple regulating and feeding mechanism for are lampsof the focusing type in which the lower and upper arc electrodes are automatically and simultaneously fed into the arc in the proper proportions.

A further object of my invention is to provide an arc lamp that will insure a substantially uniform wattage consumption throughout a trim, In focusing are lamps of the usual type of construction, the balancing of the consumable electrodes by means of weights, chains, etc, is effected for new and unconsumed electrodes. However, as the electrodes consume in the are, this initial balancing is gradually destroyed, with the result that the wattage consumption of the lamp is increased. Consequently, the satisfactoryregulation of the are lamp circuits and the arcs produced by the lamps, is rendered diflicult. But, by the use of my invention, this ditficulty is overcome and a uniform wattage consumption of the lamp is insured.

Other features of novelty of my invention will be hereinafter disclosed and pointed out with particularity in the claims annexed to, and forming a part of, this specification.

To understand the nature and scope of my invention, reference is had to the .following description and the accompanyin drawings forming a part hereof in which have disclosed an embodiment of my invention,

In the drawings, Figure l is a view, partially in elevation and partially in section, of a portion of an arc lamp constructed in accordance with my invention; Fig. 2 is a plan view of a portion of the structure shown in Fig. 1, and Fig. 3 is a view of my arc lamp, somewhat diagrammatic, taken at right angles to that shown in Feferring to Fig. 1, an upper electrode 1 cooperates with a lower alined electrode 2 to maintain an are between their opposing and adjacent ends. An electrode holder 3, which engages the upper end of-the electrode 1, is pivotally secured at 4, in any suitable manner, to the lower end of a lazytong mechanism 5. A longitudinally-disposed rod 6, projecting through a platform 7 of the are lamp, is provided, at its lower end, with an elecetrode holder 8 for the lower electrode 2, and is rigidly secured at 9 to a sliding member 19 which is pivotally connected to the upper end of the lazy-tong mechanism 5. A central tubular member 10 supports the operating mechanism of the arc lamp the lazy-tong mechanism 5 being pivotally fixed at an intermediate point 11 to the tubular member 10. Retractiou of the lazy-tong mechanism 5 is effected through a clutch ring 12 and a supporting rod 13 therefor, which, in turn, is pivotally secured to a rocker-arm 1%. At each end of the rocker-arm, I have shown magnetizable core menrbers 15 that extend into electromagnetic coils 16 which may be connected in the electrical circuit in many different ways. It is usual to connect one of the coils 16 in shunt to the are and the other coil 16 in series with the arc, the regulating functions being thus performed by the potential drop across the are and by the current flowing through the are.

In Fig. 2, it will be seen that the rocker arm 14 is provided with a bifurcated prtion 15 through which the tubular member 10 projects. Pins 16 extending through the divided portions of the rocker arm, pivotally secure it to the central tube 10. By referring to Fig. 1, it will be seen that the lazy-tong mechanism comprises duplicate sets of levers 17 and 18 which are tied together, at their upper ends, to a common member 19 which embraces the central tube 10. However, the member 19 loosely engages the central tube in order that it may freely move up and down without undue frictional resistance being developed between it and the central tube. The lower portion of the tube 10 is provided with two oppositely-disposed slots 20 through which pins 21, secured to the lower ends of the lazy tongs 17 and 18, extend. The pins 21 are secured to a sleeve member 22 which firmly embraces the electrode holder 3.

To understand more fully the operation of my lamp, reference may now be had to Fig. 3 in which the lazy tongs are shown in an extended position, as shown by the dotted lines. l/Vhen the lamp is connected to the circuit, the clutch 12 picks up the electrode l by reason of the rocking of the rocker-arm 14 As the electrode 1 advances upwardly, the sleeve member 22 and the pins 21 transmit the movement to the lazy-tong mechanism 5 which is pivotally fixed, as above mentioned, to the central tube 10 at thepoints 11. As the lower extremity of the lazy-tongs advances toward the pivots 11, the upper end of the lazy-tongs likewise advances downwardly. In turn, the rod 6 and the electrode 2 travel downwardly, thereby drawing the are between the electrodes 1 and 2. Inasmuch as the lengths of levers 23, comprising the lazy tongs 17 and 18, are so proportioned as to feed the upper and lower electrodes at the proper rate, the movement of the lower electrode 2 is properly determined with respect to the movement of the upper electrode 1. In the figures, 1 have shown that arms 2 1 of the levers 23 are twice as long as arms 25, this being the proper proportion in order to feed the upper electrode 1' into the are twice as rapidly as the lower electrode 2. Of course, it will be understood that the levers 2 1 and 25 need not necessarily be made from straight rods, as shown in the drawings, but the arms thereof may be disposed angularly with respect to each other and rigidly connected together, the object being to feed the electrodes into the are at changing rates which may vary as the carbons are consumed according as the type of lamp and the composition of the electrodes employed therein demand.

The feeding operation of the lamp illustrated is performed intermittently, the clutch ring 12 releasing the electrode 1 when the clutch ring engages the upper surface of the platform 7. This is the usual method of feeding the electrodes in many wellknown types of are lamps. The electrode 1, by reason of its greater weight and the greater weight of its appendages, will travel downwardly, thereby extending the lazytong mechanism, as shown'by the dotted lines in Fig. 3, the pins 2-1 sliding in the slots 20 which, in turn, guide the movement of the electrodes. At the same time, the lower electrode 2 moves upwardly until the arcing ends of the electrodes are brought into contact with each other. Inasmuch as the upper electrode 1 travels a fixed distance and likewise the lower electrode 2, the arc is maintained in a constant position relative to the lamp which, as above mentioned, is of the focusing type.

While 1 have herein described and illustrated, somewhat in detail, one embodiment of my invention, it is not intended that my invention, in all of its aspects, shall be limited to this particular embodiment, as it will be apparent to anyone skilled in the art that many changes may be made without departing from the spirit and scope of the appended claims.

I claim as my invention:

1. An are lamp comprising cooperating alined electrodes, a central tubular member in which the upper electrode is positioned, and lazy tongs having an intermediate point pivotally secured to said tubular member and operatively connected to feed and focus both of said electrodes.

2. An are lamp comprising cooperating alined electrodes, a central tubular member in which the upper electrode is positioned, and lever members having an intermediate point pivotally secured to said tubular member and operatively connected to feed and focus both of said electrodes.

3. An arc lamp comprising cooperating alined electrodes, a central tubular member in which the upper electrode is positioned and lever members having a point pivotally secured to said tubular member and operatively connected to feed and focus both of said electrodes.

4. An arc lamp comprising cooperating alined electrodes, a centrally disposed longitudinal electrode-inclosing member in which one of the electrodes is positioned, and a system of co-acting lever members having a point pivotally secured to said inclosing member and operatively connected to feed and focus both of said electrodes.

5. An are lamp comprising cooperating alined electrodes, a central tubular member in Which the upper electrode is positioncd, lazy tongs having an intermediate point pivotally secured to said tubular member and one end point pivotally secured to the upper electrode, and a guide member loosely embracing the tubular member and pivotally secured to the other end of the lazy tongs, the said lazy tongs being adapted to feed and focus both of said electrodes.

6. An arc lamp comprisin cooperating alined electrodes, a central tu ular member having longitudinal slots therein and adapted to embrace the upper portion of the upper electrode, lazy tongs disposed outside the tubular member having an intermediate point pivotally secured to said tubular member and one end point pivotally secured to the upper electrode through the slots, the said lazy tongs being adapted to feed and focus both of said electrodes.

In testimony whereof, I have hereunto subscribed my name this 30th day of March, 1915.

GEORGE M. LITTLE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

